EXPLANATION OF THE PLATES. 
Tke lettering is uniform tlirous^hout the Plates, and is based on the initial letters of 
O O ^ 
the words indicated : — 
C. Ceplialon. 
oc. Ocelli, parts of the compound eye. 
a.s. Antenna superior, upper antenna. 
a.i. Antenna inferior, lower antenna. 
g.c. Gland-cone. 
ep. Epistome. 
l.s. Labium superius, labrum, upper lip. 
l.i. Labium inferius, lower lip. 
VI. Mandible. 
First maxilla. 
Second maxilla. 
mxp. Maxillipeds. 
Ovfj. trit. or o.t. Triturating organs of the stomach. ' 
c. Cor, the heart. 
(jn}. First gnathopod. 
(jn.-. Second gnathopod. 
prp}, ■*, First, second, third, fourth, and fifth perteopods. 
Pl.s. Pleon-segment. 
pJp.^, 2, First, second, and third pleopods. 
plp.sp. Coupling-spines or cleft-spines of the pleopods. 
ur.^, 2, First, second, and third uropods. 
T. Telson. 
d male, ? female, young. 
As a rule iu each species all the figures of the same group, as for example the mouth 
organs or the limbs of the perseon, are drawn to the same scale, though the different 
groups are frequently drawn to different scales. The linear magnifying powers of the 
microscope used are stated by the makers to be nearly as follows : — 
“2-inch Object-glass, with No. 1 Eye-piece, 24; with No. 2 do., 40. 
1-inch do. do. do. 55 ; do. 100. 
f-inch do. do. do. 200 ; do. 350.” 
The outlines of the undissected specimen represent it as seen in liquid under a low 
magnifying power, the appendages of only one side of the animal being figured, and the 
pleopods being generally omitted altogether. 
(ZOOL. CHALL. EXP. — PART LXVII. — 1888.) 
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